#include <iostream>
#include <iomanip>

using namespace std;

int main_0011()
{
    float x, y;
    cin >> x >> y;

    if ((x >= -1) && (x <= 1) && (y >= -1) && (y <= 1)) {
        cout << "Yes";
    } else {
        cout << "No";
    }
    return 0;
}
